Adobe Acrobat Pro - scanned docs keep getting cropped

[Citizen Snips]

I'm trying to scan some handwritten notes into a pdf document using Adobe Acrobat Pro. The notes are handwritten on a regular sheet of white printer paper. The problem I'm having is that the scanned document is being cut off at the sides, so that not all of my text is showing up in the scanned document.

Is there some setting that sets margins for the scanned document? Will my scanner and/or Adobe Acrobat simply not scan outside some predefined area? Is it not possible to scan the complete area of a regular sheet of paper into a pdf file?